Antimicrobial materials such as fabrics, polymers and even children""s toys have become increasingly popular due to public concerns over epidemiological diseases and pathogens. With respect to antimicrobial fabrics, domestic and international markets have grown significantly as a result of public awareness of these potential threats. (see, Center for Disease Control and Prevention, Infection Control and Biosafety, Medical Data International. Report # RP-701530, 1992; and A. J. Rigby, et al., Textile Horizons, December 1993, 42-46). Antimicrobial clothing can be used in medicine as well as other institutional uses for such applications as, surgeon""s gowns, caps, masks, patient drapes, bandages, wipers and cover cloths of various sizes. (see, A. J. Rigby, et al. Textile Horizons, December 1993, 42-46).
Although the demand for antimicrobial textile materials is high, few of such textiles are available, especially ones that are effective against a broad spectrum of bacteria and, which are effective after multiple machine washes (see, Vigo, T. L., Biotechnology and Bioactive Polymers, Ed. C. Gebelein et al.; D. W. Kudner, Textile Chemist and Colorist, Vol. 28, No. 5, 1996, 28-30 and J. S. Cho, et al., Textile Research Journal. 67 (12), 1997, 875-880). Research and development of durable functional textiles has been active in recent years, with new methods of incorporating antibiotics as bactericidal agents into polymers being advanced. However, most of the antimicrobial functions have been achieved by using a slow-releasing model. This model works by leaching the biocidal active agent to the surface of the material thereby inactivating the microorganisms. However, this method limits the durability of the biocidal property, by not being regenerable in a convenient way.
Co-pending U.S. application Ser. No. 08/713,406, filed Sep. 13, 1996, describes durable and regenerable cellulose materials by using an innovative chemical finishing method. In that invention, treatment of cotton and polyester/cotton fabrics were finished by hydantoin derivatives, and biocidal properties were conferred by washing the treated fabrics with a chlorine laundry bleach. Chlorination of amide and imide bonds in hydantoin rings produce biocidal N-halamine sites. The N-halamine return to their precursor forms when the sites are exposed to microorganisms. The biocidal properties of the textiles can then be regenerated by using chlorine bleach. The major advantage of this chlorine regenerable finishing method are its durability, convenience and economy.
N-halamine chemistry however, is not applicable to colorized fabrics. The use of chlorine bleach decolorizes textiles. Thus, a non-bleach regenerating agent would be desirable for certain applications, especially for colored materials. Ideally for economic and convenience reasons, a regeneration process which uses water as the functional agent could be designed.
In view of the foregoing, there exists a need in the art for durable and regenerable microbicidal colored textiles. The present invention remedies such need by providing, inter alia, durable and regenerable microbicidal polymers and textiles.
The present invention provides durable and refreshable antimicrobial polymers, especially textiles, such as nylon and polyester fabrics and methods for preparing the same. These textiles have excellent colorfastness and washfastness. The antimicrobial polymers of this invention are suitable for sportswear, antiodor carpets, films, plastics and medical uses.
In one embodiment, the present invention relates to an antimicrobial polymer composition comprising: a) a polymer material having a colorant; and b) an antimicrobial agent attached to said colorant. The colorant can be a dye or a pigment. In one embodiment, the polymer is a textile, such as a fabric. In certain preferred aspects, colorants, such as dyes, are used as connectors, bridges or links, to firmly attach the microbicidal agents to the polymer. In other aspects, the dyes contain auxochromes, such as sulfonic, hydroxyl and amino groups that can be used to facilitate color shades and solubility requirements. The antimicrobial agents are amphipathic molecules. Preferably, the antimicrobial agents are quaternary ammonium salts.
In another embodiment, the present invention relates to a process for making a polymer antimicrobial comprising: a) dyeing a polymer with a colorant to form a polymer having the colorant attached thereto; and b) attaching a antimicrobial agent to the colorant, thereby making the polymer antimicrobial. The colorant can be a dye or a pigment.
After exposure to microorganisms, the antimicrobial polymers, especially textiles, can be regenerated by simply washing in water. These antimicrobial textiles are particularly useful for hygienic, medical and athletic apparel as well as antiodor fabric such as antiodor carpets.
In another embodiment, the antimicrobial agent can be attached to the polymer without the aid of a colorant. Other features, objects and advantages of the invention and its preferred embodiments will become apparent from the detailed description which follows.